Question: Express your answer as a mixed number simplified to lowest terms. $4\dfrac{2}{7}-1\dfrac{3}{8} = {?}$
Solution: Find a common denominator for the fractions: $= {4\dfrac{16}{56}}-{1\dfrac{21}{56}}$ Convert ${4\dfrac{16}{56}}$ to ${3 + \dfrac{56}{56} + \dfrac{16}{56}}$ So the problem becomes: ${3\dfrac{72}{56}}-{1\dfrac{21}{56}}$ Separate the whole numbers from the fractional parts: $= {3} + {\dfrac{72}{56}} - {1} - {\dfrac{21}{56}}$ Bring the whole numbers together and the fractions together: $= {3} - {1} + {\dfrac{72}{56}} - {\dfrac{21}{56}}$ Subtract the whole numbers: $=2 + {\dfrac{72}{56}} - {\dfrac{21}{56}}$ Subtract the fractions: $= 2+\dfrac{51}{56}$ Combine the whole and fractional parts into a mixed number: $= 2\dfrac{51}{56}$